Fill in the blanks with the correct number.
1. 4 + 8 = 9 + 3
2. 8 + 4 = 2 + 10
3. 7 + 3 = 1 + 9
4. 10 + 10 = 20 + 0
5. 4 + 12 = 10 + 6
6. 2 + 6 = 3 + 5
7. 8 + 3 = 10 + 1
8. 5 + 6 = 1 + 10
9. 4 + 10 = 9 + 5
10. 9 + 9 = 8 + 10
11. 1 + 13 = 7 + 7
12. 18 + 2 = 10 + 10
13. 5
+ 5 = 10 + 0
14. 2 + 9 = 4 + 7
15. 17 + 3 = 16 + 4
16. 16 + 4 = 17 + 3